Optimization of preparation and removal of 4-nitrophenol from activated carbon loaded nano-iron by response surface methodology

Taking 4-nitrophenol as the target pollutant, activated carbon-supported nano-iron materials were prepared by liquid phase reduction method. Taking FeSO4, concentration, NaBH4 concentration and the dosage of activated carbon as influencing factors, Box-Behnken response surface method was used to carry out three-factor and three-level experiments, and the preparation method of activated carbon-supported nano-iron materials was optimized. The results show that the interaction between FeSO4 concentration and NaBH4 concentration has a significant effect on the preparation of nano-iron materials, which plays a key role in the removal of 4-nitrophenol, and the effect of FeSO4 concentration is more significant. The interaction between the dosage of activated carbon and NaBH4 concentration is significant. The best preparation conditions of activated carbon loaded nano-iron are 2.334 g of FeSO4 solution 100 mL, 0.462 mol/L of NaBH4 solution 50mL, and the dosage of activated carbon 5.182 g. Under these conditions, the removal rate of the prepared nano-iron material can reach 98.2 % after treating 4-nitrophenol for 3 h, and the XRD pattern shows the characteristic diffraction absorption peak of Fe-0 at 2 theta = 42 - 44 degrees. After loading nano-iron, the specific surface area of activated carbon decreased 154.27 m(2)/g, and the pore diameter decreased from 2.35 run before loading to 2.26 nm after loading.